The first thing to do is call a plumber. Most blockages are found to be in the lateral which is the owner's responsibility to have cleaned and repaired if necessary. The owner is responsible for the lateral from their house to the main in the street. If the plumber finds the blockage is in the sewer main, your plumber should contact us at 607-737-6223, so we can discuss the issue with him and check the sewer main. This number is monitored after regular business hours as well.